Cisco Router Basic Commands

manager Thu, 03/09/2017 - 13:03

Show vlan

switch # show vlan brief

 
 

IT 3600 – Networks and Internetworking

Use Putty to connect to the console

Change to the privileged EXEC mode command interpreter:

> enable

See the version of the router, at the bottom shows the configuration register 0x2102 (startup config)

# show version

Erase any startup configuration that exists and reload the router:

> enable

# erase startup-config

# reload

Show router config

# show running-config

Show router config, just the section on line

# do sh run | s line

Security

Change the enable secret password

# config t

(config)# enable secret cisco (change the password to cisco)

(config)# CNTRL-Z

# copy run start

Set password

#enable password mypassword

#service password-encryption (hide passwords)

Set password

#enable password mypassword

 Remove passwords from routers

# config t

(config)# no enable secret (encrypted)

(config)# no enable password (easy to break)

(config)# CNTRL-Z

Recover password from router steps to reset a router if the password is lost as follows:

Power cycle

As it is booting Type CNTL-D or if not using a KVM hit Send Break (break/Pause)

rommon 1> confreg 0x2142

rommon 2> reset (Reboot the router)

Continue with configuration dialog? [yes/no]: no

Router>en

Router#copy start run (if you want to save the config)

OR

Router#erase startup-config (if you want to reset the router)

Router#reload (Now at factory default)

Now set new password

(config)#enable secret cisco

(config)#config-register 0x2102

(config)# CNTRL-Z

# copy run start

# wr /* short for write memory */

Set the hostname of the router to your first name:

>enable

#config t

(config)# hostname Jeff

(config)# CNTRL-Z

Create user name and set password

>enable

#config t

(config)#username cisco password cisco

(config)#do sh run | s line (show the line section of the config)

(config)#line vty 0 4

(config-line)#no password cisco

(config-line)#login local  (look at the local user database)

(config-line)#

Create password for console

>enable

#config t

(config)#line con 0

(config)#password cisco

(config)#login

(config)#exit

Use ssh, step one configure a domain name

>enable

#config t

(config)#ip domain-name mydomain.com

(config)#crypto key generate rsa general modulus 1024 (only generate after domain set)

(config)#ip ssh version 2  (enable version 2 of ssh)

(config)#transport input telnet ssh

(config)#

To connect with ssh
#ssh -l myuser 192.168.1.1
Password: cisco
RemoteRouter>exit

Interfaces

Configure the serial0/0/0 interface with an IP address and a clock rate of 64000:

>enable

#config t

(config)# interface serial 0/0/0

(config-if)# ip address 192.168.0.2  255.255.255.0

(config-if)# clock rate 64000

(config-if)# no shutdown (bring interface up)

(config)# CNTRL-Z

Ping between the routers

# ping 192.168.0.1 repeat 3

Save your configuration

# copy running-config startup-config 

                 or 
# wr /* short for write memory */

Turn off your router and then turn it back on to verify that you correctly saved the configuration

Power cycle

> enable

# sh ip int brie /* show interfaces brief */

           Or

# show running-config

Specifies which Network interface to originate the ping from cmd

         C:\users\myuser> ping /S address

Routing

Turn on Routing with OSPF

# config t

(config)# router ospf 2

(config)# network 192.168.3.0 0.0.0.255 area 0

(config)# network 192.168.4.0 0.0.0.255 area 0

(config)# CNTRL-Z

Then turned off OSPF routing

# config t

(config)# no router ospf 2

(config)# CNTRL-Z

Turn on Routing with RIP

#config t

(config)# router rip

(config)# network 192.168.3.0

(config)# network 192.168.4.0

(config)# CNTL-Z

Turned off RIP

# config t

(config)# no router rip

(config)# CNTRL-Z

Turn on EIGRP routing

#config t

(config)# router EIGRP 2

(config)# network 192.168.3.0 255.255.255.0

(config)# network 192.168.4.0 255.255.255.0

(config)# CNTRL-Z

Disable EIGRP routing

# config t

(config)# no router EIGRP 2

(config)# CNTRL-Z

Remote SSH and Telnet

Allow remote telnet

#config t

(config)# line vty 0 4

(config-line)# password cisco

(config-line)#login

(configline)#end

#wr

From one router telnet to another

telnet 192.168.1.1

Setup vlan on Cisco switch

switch#config t

switch(config)# vlan 10

switch(config-vlan)# name RED

switch(config-vlan)# exit

or

switch#vlan data  (configure vlan through the database)

switch(vlan)# vlan 20 name BLUE

switch(vlan)# exit

or

switch#conf t (configure vlan through the interface)

switch(config)# int fa0/1

switch(config-if)# switchport access vlan 30

switch(config-if)# exit

To assign  a range or ports to a vlan

switch#conf t (configure vlan through the interface)

switch(config)# int range fa0/4 - 10

switch(config-if-range)# switchport access vlan 20

switch # CNTL-Z

Show vlan

switch # show vlan brief

Assign IP address to vlan

switch#config t

switch(config)# vlan 10

switch(config-vlan)# ip address 192.168.30.10 255.255.255.0

switch(config-vlan)# no shutdown

switch(config-vlan)# exit

Turn off console logging 

(config)# no logging on

Disable DNS lookup

switch # no ip domain-lookup

See Also